Roller screens



' L. B. SzHERQU June 10,1969 I ROLLER scmssns Sheet of 2 q I Filed lay 1.2, 1967 FIG. 7

FIG. 2

INVENTOR LHRS BORJE svmv E HEROU BY (M ATTORNEYS June 10, 1969 a. s. HEROU 3,448,943

ROLLER SCREENS INVENTOR LARS BORJE svA -E HEROU ATTORNEYS 3,448,943 ROLLER SCREENS Lars Borje Svante Heron, Slatvarsgatan 24, Vastra Frolunda, Sweden Filed May 12, 1967, Ser. No. 638,054 Claims priority, applicsatigimszveden, May 16, 1966,

Int. cl. B65h 75/48 US. Cl. 242-107 3 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to roller screen mechanisms or similar winding mechanisms which comprise a screw spring which is placed around a core and secured thereto with one end, the other end of said spring being secured to a drum surrounding the spring and serving as a winding core for a flexible web or curtain.

In self-winding screens or blinds the winding power is obtained from a screw spring provided in the winding drum, said spring being tensioned when the screen or curtain is pulled down, i.e. when the flexible web is wound off from the drum. If the screen is very wide, such as several meters, and comparatively long, it is necessary to use a spring which on the one hand is very strong and on the other hand is capable of being wound (tightened) the suflicient number of revolutions around the core. It has been found that the end of the spring which is secured to the movable drum will be actuated to a considerably greater extent thaan the opposite end which is attached to the fixed core. As a result, the movable end of the spring or the drum will be brought closer and'closer to the core during the winding movement, untilthe spring is tightened around the core to such an extent, that continued rotation of the drum is prohibited, despite the fact that a substantial portion of the spring has not been utilized in the winding movement.

The present invention provides a solution to the above problem and is substantially characterised in that sleeve means consisting of one or several rotatable but axially non-displaceable sleeves are provided mounted around the core, the outer diameter of said sleeves being smaller than the inner diameter of the screw spring. The present invention is described in greater detail herebelow with reference to the accompanying drawings, wherein:

FIGURE 1 is a partly broken front view of a roller screen assembly according to one embodiment of the present invention,

FIGURE 2 is an axial section to a larger scale through a portion of the winding drum, of FIGURE 1 and FIGURE 3 is a section corresponding to FIGURE 2 showing a slightly different modified embodiment having an auxiliary sleeve.

The roller screen assembly comprises a tubular core 1 which is provided at both ends with a screw-threaded pin 2. The core 1 is surrounded by a rotatable but axially nondisplaceable sleeve means 3 which is secured against axial displacement by means of locking rings 4 secured to the core adjacent the ends of said sleeve means. The core 1 is also surrounded by a screw spring 5 which has one end secured to the core and its other end secured to a drum 6 surrounding said spring, or to United States Patent 0 3,448,943 Patented June 10, 1969 a movable end wall 7 of said ,drum, respectively. The end wall 7 and a corresponding endwall 8 at the opposite end of the drum support journalling means 9 such as ball bearings for the core 1. The pins 2 of the core have an out-of-round cross-section and are supported by brackets 10 provided with correspondingly shaped openings. A flexible web or curtain adapted to be wound around the drum, such as a web of textile or plastic material, is indicated at 11. The inner diameter of the screw spring is slightly larger than the outer diameter of the sleeve means, and the latter preferably extends from that end of the spring which is secured to the drum to approximately two thirds of the length of the screw spring.

When the web 11 is wound off from the drum the screw spring will be tensioned, whereas that portion of the spring which is adjacent the movable end wall 7 will be brought closer and closer to the sleeve 3 until it engages the sleeve, whereafter the sleeve will be brought along in the rotating movement of the screw spring.

The sleeve means 3 may be made in several separate pieces, and the length of the sleeve, or the total length of such pieces, respectively, may be equal to the length of the screw spring or shorter than the two thirds of the length of the screw spring mentioned above.

A modified embodiment of the above-described arrangement is illustrated in FIGURE 3. In this embodiment a further auxiliary sleeve 12 which is attached to the end wall 7 of the drum by means of a flange portion 15 and screws 13 projects into the space between the spring 5 and the sleeve means 3 at that end where the spring 5 is secured to the drum end movable wall 7. This has the effect that when the flexible web is wound ofi from the drum 6 and the spring 5 is thus tensioned, the first convolutions of the spring, counted from the end wall 7, will be tightened around the auxiliary sleeve 12 thereby protecting the end portion of the freely rotatable sleeve means 3 from excessive wear due to relative movement between the spring convolutions and the sleeve means, and it also has the eifect of relieving that end portion of the spring 5 which is secured to the drum end wall 7 from undue stress. The free end of the auxiliary sleeve 12 is bevelled externally as at 14 to provide a smooth transition between the spring convolutions on the auxiliary sleeve 12 and those on the sleeve 3.

What is claimed is:

1. A winding up mechanism for roller screens or the core and having one end attached thereto, a drum surrounding said spring, said drum having an end wall, a flexible web, a screw threaded pin mounted axially at each end of said core, and having an out-of-round crosssection, the opposite end of said spring being connected to said drum surrounding said spring and serving as a winding core for said flexible web constituting said roller screen or the like, characterised in that rotatable but axially non-displaceable sleeve means are provided around said core, the outer diameter of said sleeve means being smaller than the inner diameter of said screw spring, and locking rings secured to said core adjacent the ends of said sleeve means.

2. A mechanism as claimed in claim 1, characterised in that said sleeve means extends from that end of the spring which is secured to the drum to substantially two thirds of the length of said screw spring, said drum having a movable end wall and said spring being secured to said end wall.

3. A mechanism as claimed in claim 1, characterised in that a further auxiliary sleeve having an inner diameter larger than the outer diameter of said first-mentioned sleeve means and an outer diameter smaller than the inner diameter of said spring is provided between said 3 4 spring and said sleeve means at that end of the spring 1,878,710 9/1932 Watson 160-315 X which is secured to the drum, said further auxiliary sleeve 2,765,843 10/ 1956 Nilles 160318 X being secured to said drum.

WILLIAM S. BURDEN, Primary Examiner. References Cited 5 UNITED STATES PATENTS US. Cl. X.R.

718,172 1/1903 Tennis 242 -1()7,5 160-313 

